A font in the context of mottos or inscriptions as used on daggers would be a misnomer. Fonts were not used at all on blades as they are generally classified as mechanical type, rather the inscriptions we see on blades, including the style as used on "Christmas" daggers are hand lettered by a calligrapher or letter artist using a pen or stylus if on wax.
The category of lettering style is Gothic, but there are countless variations as the small anomalies we observe between motto styles is the work and individual penmanship of the calligrapher. There have been many fonts developed based on calligraphic style, like "Old English" for example, and they are routed in the classic style of penmanship. Eickhorn inscriptions for example have a typical "house" style, as do the calligraphy used by other makers, which usually relates to the finer details of characters, flourishes, decenders, etc. You won't find any exact match of motto lettering to any mechanical font, similar perhaps, but not a match.
